/*
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you under the Apache License, Version 2.0 (the
 "License"); you may not use this file except in compliance
 with the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

package org.apache.flink.connector.base.source.reader;

import org.apache.flink.api.connector.source.SourceOutput;
import org.apache.flink.connector.base.source.reader.splitreader.SplitReader;

/**
 * Emit a record to the downstream.
 *
 * @param <E> the type of the record emitted by the {@link SplitReader}
 * @param <T> the type of records that are eventually emitted to the {@link SourceOutput}.
 * @param <SplitStateT> the mutable type of split state.
 */
public interface RecordEmitter<E, T, SplitStateT> {

	/**
	 * Process and emit the records to the {@link SourceOutput}. A few recommendations to the implementation
	 * are following:
	 *
	 * <ul>
	 * 	<li>The method maybe interrupted in the middle. In that case, the same set of records will be passed
	 * 	to the record emitter again later. The implementation needs to make sure it reades
	 * 	<li>
	 * </ul>
	 *
	 * @param element The intermediate element read by the SplitReader.
	 * @param output The output to which the final records are emit to.
	 * @param splitState The state of the split.
	 */
	void emitRecord(E element, SourceOutput<T> output, SplitStateT splitState) throws Exception;
}
